Lady Melissa Percy ranks among the best shots in Britain, but to hear her tell it, her mother and sister are even better. Her two brothers and her father, the twelfth Duke of Northumberland, are all equally skilled with a side-by-side. And though she grew up in one of the United Kingdom’s largest inhabited castles—Alnwick Castle (Hogwarts to the moviegoing public) has been in the Percy family for more than seven hundred years—the Northumberland childhood she describes was one spent ranging across heather-blanketed moors and wading waist-deep into nearby waterways. “From the age of four or five, we were out in the field with Mum and Dad while they were shooting,” Percy says. “I caught my first salmon at seven and shot my first bird at eight.”

More often than not, she spent her sporting endeavors clad in outdoor gear designed for males—a practice that continued into adulthood. “There’s a real lack of useful, practical clothing for women who want to actually get involved in country sports, especially if they want something with style,” Percy says. When her marriage dissolved in 2016, she sought a new challenge and decided to fill the gap in the market by launching Mistamina, a contemporary clothing line for female field-sports enthusiasts that now includes a series of pieces inspired by her time in the American South.

The initial collection ditched traditional tweeds and stiff plus fours for a quartet of foundational basics: two shirts, a bomber jacket, and a jumper (or sweater), all with a youthful tomboy edge. “I tested designs for a year,” Percy says, going shooting nearly every weekend to ensure each Mistamina piece was as sturdy as it was stylish. Longer than a classic farmer’s jumper and nipped at the waist to flatter the female shape, the comfortable sweater, which incorporates a bit of stretch along with shoulder and elbow shooting patches, became an immediate best seller. “It’s the kind of classic you’d grab on your way out the door at 5:00 a.m. if you needed to let the dog out,” she says, or to layer under a shooting jacket.

The Percys are dog people, and to honor their loyal friends in the field, Percy names each Mistamina piece for a family pup—past or present. Her own black Labrador retriever puppy, Uni, is currently being trained in U.S. quail country near the historic Mercer Mill Plantation outside Albany, Georgia. Percy now spends November to February on that property, which her boyfriend owns. “The jumper is actually perfect for the weather in the South,” Percy says. “During quail season, you wake up and you almost need a fire in the house. But by the middle of the day, you can be down to a T-shirt in the field, and you just loop the sweater around your waist.”

When she launched her American collection, Percy led with her popular jumpers, which come in seven colors that reflect the annual Mercer Mill field trials. “Last year, I saw a group of girls all wearing purple vests and imagined each plantation with its own Mistamina jumper,” she says. There are also an updated bomber jacket and a leather shooting bag in the works. And though she’s come to love hunting quail as much as her native grouse (“Quail are quicker and smaller than grouse, but both are as exciting as the other”), her Georgia friends haven’t converted the Brit to an over-and-under shooter—yet. She still prefers her trusty Purdey side-by-side.